Breast cancer is a major cause of mortality in women. One of the factors that influences the chances of curing a patient having breast cancer is early detection of the disease. The major methods for detecting breast cancer currently in use are X-ray mammography imaging and ultrasound imaging. In detecting breast cancer, an image of the breast is generated, using one of the above mentioned imaging modalities, and a physician inspects the image to determine whether the image is indicative of breast cancer. Such inspection of images requires image analysis specialization from the physician, which adds to the cost of the cancer detecting procedure and/or limits the availability of the procedure to relatively large medical centers. Therefore, in general, only women in risk groups of breast cancer undergo tests for early detection of breast cancer. These risk groups include, for example, women above the age of about 45 and women having a family history of breast cancer. The chances that a woman in a risk group has cancer is less than 10% and therefore even many women in the risk groups do not go for regular breast cancer detection procedures as recommended.
For women not in a risk group, for example in the age group of 25-45, there are very low chances, in accordance with current practice, that their cancer will be detected at an early stage. These women, however, have a chance of about 3 to 1000 to have breast cancer, which may not be detected until the cancer is in advanced stages. Women physicians and aware women perform palpation tests in search for cancer and woman who have suspected lumps detected in their breasts by palpitation are sent for further screening by ultrasound and/or mammography and/or biopsy.
The TS2000 cancer detection system available from TransScan, described for example in Assenheimer M, Laver-Moskovitz O, Malonek D, Manor D, Nahaliel U, Nitzan R, Saad A, “The T-Scan™ technology: electrical impedance as a diagnostic tool for breast cancer detection”, Physiology Measurements 22:1-8, 2001, the disclosure of which is incorporated herein by reference, provides in addition to an image, a malignancy score on a scale with about 100 values. This score is used by the physician in addition to the image and other indicators to aid in determining the existence of cancer.
Another method for detecting breast cancer includes injecting a liquid into the breast, sucking the injected liquid from the breast and examining the sucked liquid for cancerous particles. This method, however, is very painful and therefore cannot be used for large scale cancer examination. In addition, the results require cytology and are not provided on the spot.
U.S. Pat. No. 5,800,350, to Coppleson et al., the disclosure of which is incorporated herein by reference, describes a probe adapted to apply a plurality of stimuli to a suspected tissue. According to detected responses to the stimuli, the probe provides an indication of the surface tissue type (e.g., normal, pre-cancerous/cancerous, unknown) of the suspected tissue. The probe of U.S. Pat. No. 5,800,350 is not suitable for use with the breast, as cancerous cells in the breast are not generally on the surface of the breast.
An article titled “Breast Electrical Impedance and Estrogen Use in Postmenopausal Women”, G. Piperno, S. Lenington, Mauturitas 41 (2002), the disclosure of which is incorporated herein by reference, describes a clinical test which suggests a correlation between electrical measurements on the nipple and estrogen activity in breast tissue.
Other existing methods in more limited use include infrared imaging.